The OE tires are NOT runflats. This applies to both the 18" and 19" M3 tires. Roadside assistance or patch kit and compressor, or compressor and sealant would be options. Putting a spare in the trunk works too, but adds weight and takes up space.

Tire Rack carries the ContiComfort Kit, which you can find in our Other Products section.

I got a flat in my old E90 without RF tires on a Saturday night. It was Monday evening by the time I got my car back with a tire.

Sorry, but not having a spare (or options) for all E9x's is a little silly if you ask me. At least have a space saver so you can attempt to get home.

I've never had a tire issue other than punctures. A plug kit will temporarily fix most of these, if they're not in the sidewall. This kit from Griot's is well worth the $30. Together with the compressor in the trunk it gives some piece of mind.

Yes, I'd be interested in a space-saver option for trips. I carry a plug kit as another option for puncture repair, but that won't cure a major failure.

Dear Greg,

The space saver wheel from the X6 (part number 36-11-6-768-861) mounted with a 125/70-18 space saver tire will fit on both the front and rear of the E9x M3 without a spacer. The only problem is that the center bore of the X6 wheel is a bit larger than the E9x M3's hub so you have to be very careful to center the wheel on the hub when tightening the lugs. I'd like to find an adapter to properly center the wheel on the hub but without an adapter this setp works fine at least at moderate speeds and for relatively short distances.

The space saver wheel from the X6 (part number 36-11-6-768-861) mounted with a 125/70-18 space saver tire will fit on both the front and rear of the E9x M3 without a spacer. The only problem is that the center bore of the X6 wheel is a bit larger than the E9x M3's hub so you have to be very careful to center the wheel on the hub when tightening the lugs. I'd like to find an adapter to properly center the wheel on the hub but without an adapter this setp works fine at least at moderate speeds and for relatively short distances.

Godspeed,
Tom

Thanks for that. Is that the same as use for the X3 (my post #11)? That calcs out to an inch or more smaller OD than stock. Wonder if there is a 125/80-18 available?

Edit: I just found that the Cadillac CTS uses a 135/80-18, which, at ~26.5", would be a little larger than the stock 26.3" rear.

I'm sure you could have an adapter machined pretty easily, but would be nice to find a pre-made one. Do you know the centerbore diameters? X5 is 74.1, so I assume X6 is the same? (M3 CB = 72.56).